Hello.
BEVs and hydrogen fuel cell vehicles are a more promising transportation technology for the future because they reduce greenhouse gas emissions as well as CO2 making it more 'green.' The second question is your opinion, in mine no, they should not be required but they should at least be considering.
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The correct answer to the question is: A) miles/hour and B) metre/ second.
EXPLANATION:
Before answering this question, first we have to understand speed.
The speed of a body is defined as the rate of distance travelled or the distance travelled by a body per unit time.
Hence, it is a derived quantity which is obtained from distance and time.
The unit of distance can be metre, miles, and the unit of time can be second, minutes or hour.
As speed is the distance covered per unit time, the perfect units will be miles/hour and metre/second.
Hence, the correct options are first and second.
The sound gets louder as it gets closer and when it passes is gets softer